WO2020230537A1 - Node device - Google Patents
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- WO2020230537A1 WO2020230537A1 PCT/JP2020/017069 JP2020017069W WO2020230537A1 WO 2020230537 A1 WO2020230537 A1 WO 2020230537A1 JP 2020017069 W JP2020017069 W JP 2020017069W WO 2020230537 A1 WO2020230537 A1 WO 2020230537A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/08—Arrangements for detecting or preventing errors in the information received by repeating transmission, e.g. Verdan system
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L12/40143—Bus networks involving priority mechanisms
- H04L12/4015—Bus networks involving priority mechanisms by scheduling the transmission of messages at the communication node
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L12/40006—Architecture of a communication node
- H04L12/40013—Details regarding a bus controller
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L12/403—Bus networks with centralised control, e.g. polling
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L2012/40267—Bus for use in transportation systems
- H04L2012/40273—Bus for use in transportation systems the transportation system being a vehicle
Definitions
- This disclosure relates to a node device connected to a network communication bus.
- Japanese Patent Application Publication No. 2014-027510 discloses a configuration in which data communication is performed between a plurality of node devices connected via a network communication bus.
- data may be transmitted from a plurality of node devices to the same destination node device at the same time.
- the destination node device executes the arbitration process so as to receive only the data transmitted from one node device.
- the priority information given to the data transmitted from each node device is used for mutual comparison. As a result of the comparison, only the data determined to be given the highest priority is received by the destination node device.
- the node device that transmitted the data that lost the arbitration retransmits the data at the following specified timing.
- the data is subjected to the arbitration process again.
- the specific node device may continue to lose the arbitration and the reception by the destination node device may be delayed.
- One aspect of meeting the above requirements is a node device connected to a network communication bus.
- Communication interface and A processor that causes the communication interface to transmit data to the network communication bus.
- the processor is configured to accelerate the retransmission timing at which the data is retransmitted when the transmission of the data fails.
- the node device is generally configured not to transmit data when another node device has already started transmitting data to the network communication bus. According to the above configuration, the timing of retransmitting data from the specific node device that failed to transmit is accelerated. Therefore, when the transmission timing of the node device whose transmission timing is the same as the initial one arrives, the specific node device is specified. It is possible to increase the possibility that the retransmission of data from the node device has already started. Therefore, it is possible to suppress the delay in receiving the data transmitted from the specific node device.
- the configuration of the node device is illustrated.
- the configuration of data transmitted and received between the node devices of FIG. 1 is illustrated.
- the operation of the node device of FIG. 1 is illustrated.
- the operation of the node device of FIG. 1 is illustrated.
- the operation of the node device of FIG. 1 is illustrated.
- the operation of the node device of FIG. 1 is illustrated.
- FIG. 1 illustrates a communication network 3 in which a plurality of node devices 1 are connected to a network communication bus 2. Each node device 1 is configured to be able to send and receive data D to and from each other via the network communication bus 2.
- FIG. 2 illustrates the schematic configuration of data D.
- the data D includes a header area h and a data area d.
- the header area h is identification information for identifying the node device 1 that is the source and the contents of data, and priority information for indicating the relative priority of the plurality of node devices 1 in the communication network 3. Includes.
- the data area d includes a main body of data to be transmitted / received.
- the plurality of node devices 1 include the master node device 11 and the slave node device 12.
- the master node device 11 may request the slave node device 12 to transmit data D.
- the slave node device 12 may transmit data D in response to the request.
- each node device 1 may be an ECU (Electronic Control Unit) that controls the operation of the associated in-vehicle component.
- the master node device 11 may be an ECU that performs integrated control in the vehicle.
- the slave node device 12 can be an ECU involved in a man-machine interface in the vehicle.
- the master node device 11 includes a communication interface 111 and a processor 112.
- Processor 112 generates a clock signal.
- the clock signal is output to the network communication bus 2 via the communication interface 111.
- the clock signal is received by each slave node device 12 via the network communication bus 2.
- the clock signal is used to synchronize various processes performed between the master node device 11 and each slave node device 12.
- the processor 112 can be realized by a general-purpose microprocessor that operates in cooperation with a general-purpose memory. Examples of general-purpose microprocessors include CPUs, MPUs, and GPUs. ROM and RAM can be exemplified as the general-purpose memory. In this case, a computer program capable of executing the processing described later may be stored in the ROM. The processor 112 specifies at least a part of the computer program stored in the ROM, expands it on the RAM, and performs the above-described processing in cooperation with the RAM. The processor 112 may be realized by a dedicated integrated circuit such as a microcontroller, ASIC, or FPGA capable of executing a computer program that realizes the processing described later. The processor 112 may be realized by a combination of a general-purpose microprocessor and a dedicated integrated circuit.
- the slave node device 12 includes a communication interface 121 and a processor 122.
- the processor 122 causes the communication interface 121 to transmit the data D to the network communication bus 2 in response to the request of the master node device 11.
- the processor 122 can be realized by a dedicated integrated circuit such as a microcontroller, ASIC, or FPGA that can execute a computer program that realizes the processing described later.
- the master node device 11 is configured to be able to transmit a transmission permission signal P that permits all slave node devices 12 to transmit data to the network communication bus 2.
- the transmission permission signal P is generated by the processor 112 of the master node device 11 and transmitted from the communication interface 111.
- the processor 122 of each slave node device 12 determines whether the communication interface 121 has received the transmission permission signal P (STEP 1). The determination is repeated until the transmission permission signal P is received (NO in STEP1).
- the processor 122 determines whether or not the specified transmission timing has arrived (STEP 2). As illustrated in FIG. 4, the transmission timing is defined based on the time length T1 after the transmission permission signal P is received. In the initial state, the time length T1 is the same for all slave node devices 12.
- the time length T1 is determined based on the clock signal transmitted from the master node device 11.
- the time length T1 is, for example, 300 microseconds.
- the processor 122 determines whether the specified time length T1 has elapsed. The determination is repeated until the time length T1 elapses (NO in STEP2).
- the processor 122 When it is determined that the specified transmission timing has arrived (YES in STEP 2), the processor 122 starts transmitting the generated data (STEP 3).
- the data is transmitted from the communication interface 111 to the network communication bus 2.
- FIG. 4 shows an example in which the slave node device A and the slave node device B transmit data in response to a request from the master node device.
- the slave node device A transmits the data D1.
- the slave node device B transmits the data D2.
- the master node device 11 can receive only data transmitted from one of the plurality of slave node devices 12 as a response to a certain transmission permission signal P. Therefore, an arbitration process for determining one data received by the master node device 11 is performed.
- priorities are predetermined between the plurality of slave node devices 12 connected to the network communication bus 2.
- the priority is determined based on the urgency of the data to be transmitted.
- the priority information indicating the priority is included in the header area of the transmitted data.
- the priority information can be represented by at least one bit contained in the header area. For example, it is determined that the case where the bit is "0" has a higher priority than the case where the bit is "1".
- the priority information is represented by a plurality of bits, the bits closest to the beginning of the bit string are compared, and it is determined that the priority of the data associated with the bit string in which "1" appears earlier is low.
- the priority of the slave node device A is set higher than the priority of the slave node device B.
- the priority information included in the header area of the data D1 and the priority information included in the header area of the data D2 are compared.
- the transmission of the data area following the header area of the data D1 is continued.
- the transmission of the data D2 that has lost the arbitration due to the information contained in the header area is interrupted.
- Each slave node device 12 monitors the content of the data actually transmitted to the network communication bus 2. If the data generated as the transmission target and the data actually transmitted are different, the processor 122 determines that the data transmission has failed. In the case of the above example, the data D1 generated in the slave node device A and the data D1 actually transmitted match. On the other hand, since the transmission of the data D2 generated in the slave node device B is interrupted, the generated data and the actually transmitted data are different. Therefore, the processor of the slave node device B determines that the transmission of the data D2 has failed.
- the processor 122 of each slave node device 12 determines whether or not the data transmission has failed as described above (STEP 4). When it is determined that the data transmission is successful (NO in STEP4), the process ends.
- the master node device 11 periodically outputs a transmission permission signal P.
- the data whose transmission has not been completed is retransmitted as a response to the next transmission permission signal P.
- the processor 122 of the slave node device 12 performs a process of accelerating the retransmission timing at which the data is retransmitted. (STEP5).
- the time length from the reception of the transmission permission signal P to the start of data retransmission is shortened from the initial value T1 to T2.
- the time length T2 is, for example, 200 microseconds.
- the processor 122 determines whether or not the specified retransmission timing has arrived (STEP 6). That is, the processor 122 determines whether the time length T2 has elapsed since the transmission permission signal P was received by the communication interface 121. At this time, it is determined whether or not the transmission permission signal P has been received in the same manner as in STEP 1, but the illustration is omitted. The determination is repeated until the time length T2 elapses (NO in STEP 6).
- the processor 122 When it is determined that the specified retransmission timing has arrived (YES in STEP 6), the processor 122 starts the data retransmission (STEP 7). The data is transmitted from the communication interface 121 to the network communication bus 2. When the retransmission is completed, the process ends.
- the transmission permission signal P transmitted from the master node device is received by the slave node device A and the slave node device B
- the data D1 is transmitted and the data D2 is transmitted after the time length T1 elapses. Transmission starts at the same time.
- the arbitration process is performed based on the priority set for the slave node device A and the slave node device B, and the transmission of the data D2 that has lost the arbitration is interrupted. Therefore, the data D2 is then subjected to retransmission as a response to the transmission permission signal P transmitted from the master node device.
- the arbitration process is not performed. The transmission of data D2 is completed without any problem.
- FIG. 6 illustrates a case where the slave node device A transmits the data D3 in addition to the slave node device B retransmitting the data D2 as a response to the next transmission permission signal P. Since the time length T1 from the reception of the transmission permission signal P to the start of data transmission is invariant, the data D2 is retransmitted and the data D3 is transmitted at the same time. Therefore, the arbitration process is performed again between the data D2 and the data D3. Since the priorities of the slave node device A and the slave node device B do not change, the data D2 loses arbitration again and is subject to retransmission. In this way, the data transmitted from the specific slave node device may continue to lose the arbitration, and the reception of the data by the master node device may be delayed.
- Each slave node device 12 is configured not to perform data transmission when another slave node device 12 has already started data transmission to the network communication bus 2. For example, it may be configured that data transmission is started when the state in which the signal level of the network communication bus 2 corresponds to "1" continues for a certain period of time or longer. If communication has already been started by the other slave node device 12, such a signal level state cannot be obtained.
- the timing of retransmitting the data from the slave node device that failed to be transmitted due to the arbitration loss is accelerated, so that the data transmitted from the specific slave node device can be obtained. It becomes easier to avoid the situation of continuing to lose the mediation. Specifically, since the retransmission timing of the data D2 from the slave node device B has been advanced, the slave node device when the transmission timing of the data D3 from the slave node device A, which is the same as the initial transmission timing, arrives. Retransmission of data D2 from B has already started. Therefore, the data D3 is not transmitted. The data D3 is further subject to retransmission in response to the next transmission permission signal P. Therefore, it is possible to suppress the delay in reception due to the arbitration loss of the data transmitted from the specific slave node device.
- Each slave node device 12 does not change the priority information included in the data header area when performing the process of accelerating the retransmission timing. That is, the relationship regarding the priority between the plurality of predetermined slave node devices is maintained. In the case of the example shown in FIG. 4, there is no change in the fact that the priority of the slave node device A is higher than the priority of the slave node device B. However, as far as the data D2 that has lost the arbitration is concerned, the priority of the slave node device B is tentatively higher than the priority of the slave node device A by accelerating the retransmission timing.
- FIG. 4 illustrates a conflict between data transmitted from the two slave node devices 12.
- data arbitration loss may occur in a plurality of slave node devices.
- conflict occurs again between the data retransmitted by the plurality of slave node devices, and the arbitration process is performed.
- the data D2 to be retransmitted may lose arbitration again due to the data D4 (not shown) transmitted from the slave node device C (not shown) to which the priority is given higher than that of the slave node device B. It is possible.
- the processor 122 of each slave node device 12 may perform a process of further advancing the retransmission timing each time the data transmission fails, as illustrated by the broken line in FIG. ..
- the processor 122 when the data D2 loses the arbitration with the data D4 and fails to transmit again (YES in STEP4), the processor 122 performs a process of further accelerating the timing at which the data D2 is retransmitted (YES in STEP4). STEP5).
- the time length from the next reception of the transmission permission signal P to the start of data retransmission is shortened from the current value T2 to T3 (not shown).
- the time length T3 is, for example, 100 microseconds.
- the probability that the data D2 will lose the arbitration at the time of the next response to the transmission permission signal P transmitted from the master node device can be further reduced. Therefore, it is possible to further suppress the delay in reception due to the loss of arbitration of the data transmitted from the specific slave node device.
- the time length that defines the retransmission timing is shortened from 300 microseconds to 200 microseconds and from 200 microseconds to 100 microseconds. ing. That is, the amount of time for which the retransmission timing is advanced is set to 100 microseconds. However, the amount of time can be determined based on the time length T1 that defines the initial transmission timing and the number of slave node devices 12 that can simultaneously transmit data to the network communication bus 2.
- the time length from the reception of the transmission permission signal P to the start of data retransmission is 10 steps from the initial time length T1.
- the above amount of time can be defined as a value that can be shortened. According to such a configuration, the data transmitted from the specific slave node device 12 does not continue to lose the arbitration until the end. At this time, it is not necessary that the number of slave node devices 12 capable of simultaneously transmitting data to the network communication bus 2 and the number of steps capable of shortening the time length until the start of retransmission are the same.
- Transmission from a specific slave node device 12 by increasing the number of steps that can shorten the time until the start of retransmission is within the range equal to or less than the number of slave node devices 12 that can simultaneously transmit data to the network communication bus 2. It is possible to reduce the possibility that the data to be generated will continue to lose the mediation.
- the amount of time for which the retransmission timing is advanced is set to be longer than the time required for 1-bit data transmission on the network communication bus 2.
- the time required for 1-bit data transmission is determined based on the clock frequency transmitted from the master node device 11. With such a configuration, it is possible to reliably perform the retransmission of the data that has lost the arbitration.
- the communication network 3 operates based on the polling type CXPI standard, and the plurality of node devices 1 connected to the network communication bus 2 include the master node device 11 and the slave node device 12. I'm out.
- the above-mentioned process of accelerating the re-transmission timing of the data that has failed to be transmitted can also be applied to a communication network in which there is no distinction between a master and a slave for a plurality of node devices 1.
- a communication network that operates based on a carrier sense type CAN (Control Area Network) standard can be mentioned.
- the cause of data transmission failure is not limited to mediation loss. Due to the occupation of the network communication bus by data transmission of other node devices, it may not be possible to transmit data at the specified timing. Such a situation is also an example of data transmission failure.
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Abstract
This node device (1), which is connected to a network communication bus (2), comprises a communication interface (121) and a processor (122). The processor (122) causes the communication interface (121) to transmit data (D) to the network communication bus (2). The processor (122) is configured to advance retransmission timing at which the data (D) is retransmitted, when failing to transmit the data (D).
Description
本開示は、ネットワーク通信バスに接続されるノード装置に関連する。
This disclosure relates to a node device connected to a network communication bus.
日本国特許出願公開2014-027510号公報は、ネットワーク通信バスを介して接続された複数のノード装置間でデータ通信が行なわれる構成を開示している。当該構成においては、複数のノード装置から同じ宛先ノード装置へ同時にデータが送信される場合がある。このようにしてデータ送信の競合が生じたとき、宛先ノード装置においては、一つのノード装置から送信されたデータのみを受信するように調停処理が実行される。具体的には、各ノード装置から送信されるデータに付与されている優先度情報が、相互比較に供される。比較の結果として最も高い優先度が付与されていると判断されたデータのみが、宛先ノード装置に受信される。
Japanese Patent Application Publication No. 2014-027510 discloses a configuration in which data communication is performed between a plurality of node devices connected via a network communication bus. In this configuration, data may be transmitted from a plurality of node devices to the same destination node device at the same time. When a data transmission conflict occurs in this way, the destination node device executes the arbitration process so as to receive only the data transmitted from one node device. Specifically, the priority information given to the data transmitted from each node device is used for mutual comparison. As a result of the comparison, only the data determined to be given the highest priority is received by the destination node device.
調停に負けたデータを送信したノード装置は、次の規定されたタイミングにおいて当該データの再送信を行なう。当該データについて他のノード装置から送信されたデータとの競合が生じると、当該データは、再び調停処理に供される。当該データに付与された優先度によっては、特定のノード装置が調停に負け続けて宛先ノード装置による受信が遅れる場合がありうる。
The node device that transmitted the data that lost the arbitration retransmits the data at the following specified timing. When a conflict occurs with the data transmitted from another node device for the data, the data is subjected to the arbitration process again. Depending on the priority given to the data, the specific node device may continue to lose the arbitration and the reception by the destination node device may be delayed.
したがって、特定のノード装置から送信されるデータの受信の遅延を抑制することが求められている。
Therefore, it is required to suppress the delay in receiving the data transmitted from the specific node device.
上記の要求に応えるための一態様は、ネットワーク通信バスに接続されるノード装置であって、
通信インターフェースと、
前記通信インターフェースに前記ネットワーク通信バスへのデータの送信を行なわせるプロセッサと、
を備えており、
前記プロセッサは、前記データの送信に失敗した場合、当該データが再送信される再送信タイミングを早めるように構成されている。 One aspect of meeting the above requirements is a node device connected to a network communication bus.
Communication interface and
A processor that causes the communication interface to transmit data to the network communication bus.
Is equipped with
The processor is configured to accelerate the retransmission timing at which the data is retransmitted when the transmission of the data fails.
通信インターフェースと、
前記通信インターフェースに前記ネットワーク通信バスへのデータの送信を行なわせるプロセッサと、
を備えており、
前記プロセッサは、前記データの送信に失敗した場合、当該データが再送信される再送信タイミングを早めるように構成されている。 One aspect of meeting the above requirements is a node device connected to a network communication bus.
Communication interface and
A processor that causes the communication interface to transmit data to the network communication bus.
Is equipped with
The processor is configured to accelerate the retransmission timing at which the data is retransmitted when the transmission of the data fails.
ノード装置は、他のノード装置がネットワーク通信バスへのデータ送信を既に開始している場合は送信を行なわないように構成されていることが一般的である。上記のような構成によれば、送信に失敗した特定のノード装置からのデータの再送信タイミングが早められるので、送信タイミングが当初のままであるノード装置の送信タイミングが到来したときには、当該特定のノード装置からのデータの再送信が既に開始されている可能性を高めることができる。したがって、特定のノード装置から送信されるデータの受信の遅延を抑制できる。
The node device is generally configured not to transmit data when another node device has already started transmitting data to the network communication bus. According to the above configuration, the timing of retransmitting data from the specific node device that failed to transmit is accelerated. Therefore, when the transmission timing of the node device whose transmission timing is the same as the initial one arrives, the specific node device is specified. It is possible to increase the possibility that the retransmission of data from the node device has already started. Therefore, it is possible to suppress the delay in receiving the data transmitted from the specific node device.
添付の図面を参照しつつ、実施形態の例について以下詳細に説明する。以下の説明に用いられる各図面においては、各要素を認識可能な大きさとするために縮尺が適宜変更されている。
An example of the embodiment will be described in detail below with reference to the attached drawings. In each of the drawings used in the following description, the scale is appropriately changed so that each element can be recognized.
図1は、複数のノード装置1がネットワーク通信バス2に接続されている通信ネットワーク3を例示している。各ノード装置1は、ネットワーク通信バス2を介して相互にデータDを送受信できるように構成されている。
FIG. 1 illustrates a communication network 3 in which a plurality of node devices 1 are connected to a network communication bus 2. Each node device 1 is configured to be able to send and receive data D to and from each other via the network communication bus 2.
図2は、データDの概略構成を例示している。データDは、ヘッダ領域hとデータ領域dを含んでいる。ヘッダ領域hは、送信元であるノード装置1やデータの内容を識別するための識別情報や、通信ネットワーク3における複数のノード装置1同士の相対的な優先度の高低を示すための優先度情報を含んでいる。データ領域dは、送受信されるデータの本体を含んでいる。
FIG. 2 illustrates the schematic configuration of data D. The data D includes a header area h and a data area d. The header area h is identification information for identifying the node device 1 that is the source and the contents of data, and priority information for indicating the relative priority of the plurality of node devices 1 in the communication network 3. Includes. The data area d includes a main body of data to be transmitted / received.
一例として、ポーリング方式のCXPI(Clock Extension Peripheral Interface)規格に基づいて通信ネットワーク3が動作する構成を説明する。この場合、複数のノード装置1は、マスタノード装置11とスレーブノード装置12を含む。マスタノード装置11は、スレーブノード装置12に対してデータDの送信を要求しうる。スレーブノード装置12は、当該要求に対してデータDを送信しうる。
As an example, a configuration in which the communication network 3 operates based on the polling method CXPI (Clock Extension Peripheral Interface) standard will be described. In this case, the plurality of node devices 1 include the master node device 11 and the slave node device 12. The master node device 11 may request the slave node device 12 to transmit data D. The slave node device 12 may transmit data D in response to the request.
このような通信ネットワーク3は、例えば車両に搭載されうる。この場合、各ノード装置1は、対応づけられた車載部品の動作を制御するECU(Electronic Control Unit)でありうる。マスタノード装置11は、車両において統括的な制御を行なうECUでありうる。スレーブノード装置12は、当該車両においてマンマシンインターフェースに関与するECUでありうる。
Such a communication network 3 can be mounted on a vehicle, for example. In this case, each node device 1 may be an ECU (Electronic Control Unit) that controls the operation of the associated in-vehicle component. The master node device 11 may be an ECU that performs integrated control in the vehicle. The slave node device 12 can be an ECU involved in a man-machine interface in the vehicle.
マスタノード装置11は、通信インターフェース111とプロセッサ112を備えている。プロセッサ112は、クロック信号を生成する。クロック信号は、通信インターフェース111を介してネットワーク通信バス2へ出力される。クロック信号は、ネットワーク通信バス2を介して各スレーブノード装置12に受信される。クロック信号は、マスタノード装置11と各スレーブノード装置12との間で行なわれる各種処理の同期をとるために使用される。
The master node device 11 includes a communication interface 111 and a processor 112. Processor 112 generates a clock signal. The clock signal is output to the network communication bus 2 via the communication interface 111. The clock signal is received by each slave node device 12 via the network communication bus 2. The clock signal is used to synchronize various processes performed between the master node device 11 and each slave node device 12.
プロセッサ112は、汎用メモリと協働して動作する汎用マイクロプロセッサにより実現されうる。汎用マイクロプロセッサとしては、CPU、MPU、GPUが例示されうる。汎用メモリとしては、ROMやRAMが例示されうる。この場合、ROMには、後述する処理を実行可能なコンピュータプログラムが記憶されうる。プロセッサ112は、ROM上に記憶されたコンピュータプログラムの少なくとも一部を指定してRAM上に展開し、RAMと協働して上述した処理を実行する。プロセッサ112は、後述する処理を実現するコンピュータプログラムを実行可能なマイクロコントローラ、ASIC、FPGAなどの専用集積回路によって実現されてもよい。プロセッサ112は、汎用マイクロプロセッサと専用集積回路の組合せによって実現されてもよい。
The processor 112 can be realized by a general-purpose microprocessor that operates in cooperation with a general-purpose memory. Examples of general-purpose microprocessors include CPUs, MPUs, and GPUs. ROM and RAM can be exemplified as the general-purpose memory. In this case, a computer program capable of executing the processing described later may be stored in the ROM. The processor 112 specifies at least a part of the computer program stored in the ROM, expands it on the RAM, and performs the above-described processing in cooperation with the RAM. The processor 112 may be realized by a dedicated integrated circuit such as a microcontroller, ASIC, or FPGA capable of executing a computer program that realizes the processing described later. The processor 112 may be realized by a combination of a general-purpose microprocessor and a dedicated integrated circuit.
スレーブノード装置12は、通信インターフェース121とプロセッサ122を備えている。プロセッサ122は、マスタノード装置11の要求に応じて、通信インターフェース121にネットワーク通信バス2へのデータDの送信を行なわせる。プロセッサ122は、後述する処理を実現するコンピュータプログラムを実行可能なマイクロコントローラ、ASIC、FPGAなどの専用集積回路によって実現されうる。
The slave node device 12 includes a communication interface 121 and a processor 122. The processor 122 causes the communication interface 121 to transmit the data D to the network communication bus 2 in response to the request of the master node device 11. The processor 122 can be realized by a dedicated integrated circuit such as a microcontroller, ASIC, or FPGA that can execute a computer program that realizes the processing described later.
図3から図6を参照しつつ、各スレーブノード装置12のプロセッサ122により実行される処理の一例について説明する。図4に例示されるように、マスタノード装置11は、全てのスレーブノード装置12に対してデータの送信を許可する送信許可信号Pを、ネットワーク通信バス2へ送信可能に構成されている。送信許可信号Pは、マスタノード装置11のプロセッサ112により生成され、通信インターフェース111より送信される。
An example of processing executed by the processor 122 of each slave node device 12 will be described with reference to FIGS. 3 to 6. As illustrated in FIG. 4, the master node device 11 is configured to be able to transmit a transmission permission signal P that permits all slave node devices 12 to transmit data to the network communication bus 2. The transmission permission signal P is generated by the processor 112 of the master node device 11 and transmitted from the communication interface 111.
図3に例示されるように、各スレーブノード装置12のプロセッサ122は、通信インターフェース121が送信許可信号Pを受信したかを判断する(STEP1)。送信許可信号Pが受信されるまで、当該判断が繰り返される(STEP1においてNO)。
As illustrated in FIG. 3, the processor 122 of each slave node device 12 determines whether the communication interface 121 has received the transmission permission signal P (STEP 1). The determination is repeated until the transmission permission signal P is received (NO in STEP1).
送信許可信号Pが受信されたと判断されると(STEP1においてYES)、プロセッサ122は、規定された送信タイミングが到来したかを判断する(STEP2)。図4に例示されるように、送信タイミングは、送信許可信号Pが受信されてからの時間長T1に基づいて規定される。初期状態において、時間長T1は、全てのスレーブノード装置12について同一である。
When it is determined that the transmission permission signal P has been received (YES in STEP 1), the processor 122 determines whether or not the specified transmission timing has arrived (STEP 2). As illustrated in FIG. 4, the transmission timing is defined based on the time length T1 after the transmission permission signal P is received. In the initial state, the time length T1 is the same for all slave node devices 12.
時間長T1は、マスタノード装置11から送信されるクロック信号に基づいて定められる。時間長T1は、例えば300マイクロ秒である。換言すると、プロセッサ122は、規定された時間長T1が経過したかを判断する。時間長T1が経過するまで、当該判断が繰り返される(STEP2においてNO)。
The time length T1 is determined based on the clock signal transmitted from the master node device 11. The time length T1 is, for example, 300 microseconds. In other words, the processor 122 determines whether the specified time length T1 has elapsed. The determination is repeated until the time length T1 elapses (NO in STEP2).
規定された送信タイミングが到来したと判断されると(STEP2においてYES)、プロセッサ122は、生成されたデータの送信を開始する(STEP3)。データは、通信インターフェース111からネットワーク通信バス2へ送信される。図4においては、マスタノード装置からの要求に応じてスレーブノード装置Aとスレーブノード装置Bがデータを送信する例が示されている。スレーブノード装置Aは、データD1を送信する。スレーブノード装置Bは、データD2を送信する。
When it is determined that the specified transmission timing has arrived (YES in STEP 2), the processor 122 starts transmitting the generated data (STEP 3). The data is transmitted from the communication interface 111 to the network communication bus 2. FIG. 4 shows an example in which the slave node device A and the slave node device B transmit data in response to a request from the master node device. The slave node device A transmits the data D1. The slave node device B transmits the data D2.
前述のように、初期状態においては全てのスレーブノード装置12について時間長T1が同一であるので、複数のスレーブノード装置12から同時にデータ送信が開始される場合がありうる。他方、マスタノード装置11は、ある送信許可信号Pへの応答として受信できるデータは、当該複数のスレーブノード装置12の一つから送信されたものだけである。したがって、マスタノード装置11に受信される一つのデータを決定するための調停処理が行なわれる。
As described above, since the time length T1 is the same for all slave node devices 12 in the initial state, data transmission may be started from a plurality of slave node devices 12 at the same time. On the other hand, the master node device 11 can receive only data transmitted from one of the plurality of slave node devices 12 as a response to a certain transmission permission signal P. Therefore, an arbitration process for determining one data received by the master node device 11 is performed.
図2を参照して説明したように、ネットワーク通信バス2に接続されている複数のスレーブノード装置12同士の間には、優先度が予め定められている。優先度は、送信されるデータの緊急性などに基づいて定められる。優先度を示す優先度情報は、送信されるデータのヘッダ領域に含まれている。優先度情報は、ヘッダ領域に含まれる少なくとも一つのビットにより表現されうる。例えば、当該ビットが「0」である場合の方が、当該ビットが「1」である場合よりも優先度が高いと判断される。優先度情報が複数のビットにより表現される場合、ビット列の先頭に近いビット同士から比較がなされ、より早く「1」が現れたビット列に対応付けられたデータの優先度が低いと判断される。
As described with reference to FIG. 2, priorities are predetermined between the plurality of slave node devices 12 connected to the network communication bus 2. The priority is determined based on the urgency of the data to be transmitted. The priority information indicating the priority is included in the header area of the transmitted data. The priority information can be represented by at least one bit contained in the header area. For example, it is determined that the case where the bit is "0" has a higher priority than the case where the bit is "1". When the priority information is represented by a plurality of bits, the bits closest to the beginning of the bit string are compared, and it is determined that the priority of the data associated with the bit string in which "1" appears earlier is low.
図4に示される例においては、スレーブノード装置Aの優先度がスレーブノード装置Bの優先度よりも高く設定されているとする。この場合、データD1のヘッダ領域に含まれる優先度情報とデータD2のヘッダ領域に含まれる優先度情報が比較される。結果として、データD1が調停に勝ち、データD2が調停に負ける。この場合、データD1のヘッダ領域に後続するデータ領域の送信が継続される。他方、ヘッダ領域に含まれる情報で調停に負けたデータD2の送信は中断される。
In the example shown in FIG. 4, it is assumed that the priority of the slave node device A is set higher than the priority of the slave node device B. In this case, the priority information included in the header area of the data D1 and the priority information included in the header area of the data D2 are compared. As a result, data D1 wins the arbitration and data D2 loses the arbitration. In this case, the transmission of the data area following the header area of the data D1 is continued. On the other hand, the transmission of the data D2 that has lost the arbitration due to the information contained in the header area is interrupted.
各スレーブノード装置12は、実際にネットワーク通信バス2へ送信されたデータの内容を監視している。送信対象として生成されたデータと実際に送信されたデータが相違している場合、プロセッサ122は、データの送信に失敗したと判断する。上記の例の場合、スレーブノード装置Aにおいて生成されたデータD1と実際に送信されたデータD1は一致している。他方、スレーブノード装置Bにおいて生成されたデータD2の送信は中断されているので、生成されたデータと実際に送信されたデータが相違する。したがって、スレーブノード装置Bのプロセッサは、データD2の送信に失敗したと判断する。
Each slave node device 12 monitors the content of the data actually transmitted to the network communication bus 2. If the data generated as the transmission target and the data actually transmitted are different, the processor 122 determines that the data transmission has failed. In the case of the above example, the data D1 generated in the slave node device A and the data D1 actually transmitted match. On the other hand, since the transmission of the data D2 generated in the slave node device B is interrupted, the generated data and the actually transmitted data are different. Therefore, the processor of the slave node device B determines that the transmission of the data D2 has failed.
図3に例示されるように、各スレーブノード装置12のプロセッサ122は、上記のようにしてデータの送信に失敗したかを判断する(STEP4)。データの送信に成功したと判断されると(STEP4においてNO)、処理は終了する。
As illustrated in FIG. 3, the processor 122 of each slave node device 12 determines whether or not the data transmission has failed as described above (STEP 4). When it is determined that the data transmission is successful (NO in STEP4), the process ends.
図4に例示されるように、マスタノード装置11は、定期的に送信許可信号Pを出力する。送信が完了しなかったデータは、次の送信許可信号Pに対する応答として、再送信に供される。図3に例示されるように、データの送信に失敗したと判断されると(STEP4においてYES)、スレーブノード装置12のプロセッサ122は、当該データが再送信される再送信タイミングを早める処理を行なう(STEP5)。換言すると、送信許可信号Pが受信されてからデータの再送信が開始されるまでの時間長が、初期値であるT1からT2へ短縮される。時間長T2は、例えば200マイクロ秒である。
As illustrated in FIG. 4, the master node device 11 periodically outputs a transmission permission signal P. The data whose transmission has not been completed is retransmitted as a response to the next transmission permission signal P. As illustrated in FIG. 3, when it is determined that the data transmission has failed (YES in STEP 4), the processor 122 of the slave node device 12 performs a process of accelerating the retransmission timing at which the data is retransmitted. (STEP5). In other words, the time length from the reception of the transmission permission signal P to the start of data retransmission is shortened from the initial value T1 to T2. The time length T2 is, for example, 200 microseconds.
続いてプロセッサ122は、規定された再送信タイミングが到来したかを判断する(STEP6)。すなわち、プロセッサ122は、送信許可信号Pが通信インターフェース121に受信されてから時間長T2が経過したかを判断する。このとき、STEP1と同様にして送信許可信号Pが受信されたかの判断がなされるが、図示は省略されている。時間長T2が経過するまで、当該判断が繰り返される(STEP6においてNO)。
Subsequently, the processor 122 determines whether or not the specified retransmission timing has arrived (STEP 6). That is, the processor 122 determines whether the time length T2 has elapsed since the transmission permission signal P was received by the communication interface 121. At this time, it is determined whether or not the transmission permission signal P has been received in the same manner as in STEP 1, but the illustration is omitted. The determination is repeated until the time length T2 elapses (NO in STEP 6).
規定された再送信タイミングが到来したと判断されると(STEP6においてYES)、プロセッサ122は、データの再送信を開始する(STEP7)。データは、通信インターフェース121からネットワーク通信バス2へ送信される。再送信が完了すると、処理は終了する。
When it is determined that the specified retransmission timing has arrived (YES in STEP 6), the processor 122 starts the data retransmission (STEP 7). The data is transmitted from the communication interface 121 to the network communication bus 2. When the retransmission is completed, the process ends.
このような構成の有利性について、図5と図6に示される比較例を参照しつつ説明する。比較例においては、送信許可信号Pの応答としてデータの送信が開始されるタイミング(すなわち時間長T1)が不変である。スレーブノード装置Aとスレーブノード装置Bの優先度に係る関係は、図4に示される例と同じである。
The advantages of such a configuration will be described with reference to the comparative examples shown in FIGS. 5 and 6. In the comparative example, the timing (that is, the time length T1) at which data transmission is started as a response of the transmission permission signal P is unchanged. The relationship regarding the priority of the slave node device A and the slave node device B is the same as the example shown in FIG.
図5に例示されるように、マスタノード装置から送信された送信許可信号Pがスレーブノード装置Aとスレーブノード装置Bに受信されると、時間長T1の経過後に、データD1の送信とデータD2の送信が同時に開始される。その結果、スレーブノード装置Aとスレーブノード装置Bについて設定された優先度に基づいて調停処理が行なわれ、調停に負けたデータD2の送信は中断される。したがって、データD2は、次にマスタノード装置から送信される送信許可信号Pへの応答として、再送信に供される。同図に示される例においては、スレーブノード装置Bのみが次の送信許可信号Pに対してデータを送信するので、調停処理は行なわれない。データD2の送信は問題なく完了する。
As illustrated in FIG. 5, when the transmission permission signal P transmitted from the master node device is received by the slave node device A and the slave node device B, the data D1 is transmitted and the data D2 is transmitted after the time length T1 elapses. Transmission starts at the same time. As a result, the arbitration process is performed based on the priority set for the slave node device A and the slave node device B, and the transmission of the data D2 that has lost the arbitration is interrupted. Therefore, the data D2 is then subjected to retransmission as a response to the transmission permission signal P transmitted from the master node device. In the example shown in the figure, since only the slave node device B transmits data to the next transmission permission signal P, the arbitration process is not performed. The transmission of data D2 is completed without any problem.
図6は、次の送信許可信号Pへの応答として、スレーブノード装置BによるデータD2の再送信に加えてスレーブノード装置AによるデータD3の送信が行なわれる場合を例示している。送信許可信号Pの受信からデータ送信開始までの時間長T1は不変であるので、データD2の再送信とデータD3の送信は同時に行なわれる。したがって、データD2とデータD3の間で再び調停処理が行なわれる。スレーブノード装置Aとスレーブノード装置Bの優先度も変わらないので、データD2は再び調停に負けて再送信の対象とされる。このようにして、特定のスレーブノード装置から送信されるデータが調停に負け続け、マスタノード装置による当該データの受信が遅れる場合がありうる。
FIG. 6 illustrates a case where the slave node device A transmits the data D3 in addition to the slave node device B retransmitting the data D2 as a response to the next transmission permission signal P. Since the time length T1 from the reception of the transmission permission signal P to the start of data transmission is invariant, the data D2 is retransmitted and the data D3 is transmitted at the same time. Therefore, the arbitration process is performed again between the data D2 and the data D3. Since the priorities of the slave node device A and the slave node device B do not change, the data D2 loses arbitration again and is subject to retransmission. In this way, the data transmitted from the specific slave node device may continue to lose the arbitration, and the reception of the data by the master node device may be delayed.
各スレーブノード装置12は、他のスレーブノード装置12がネットワーク通信バス2へのデータ送信を既に開始している場合、送信を行なわないように構成されている。例えば、ネットワーク通信バス2の信号レベルが「1」に対応する状態が一定期間以上継続している場合に、データの送信が開始されるように構成されうる。他のスレーブノード装置12により既に通信が開始されていると、このような信号レベルの状態は得られない。
Each slave node device 12 is configured not to perform data transmission when another slave node device 12 has already started data transmission to the network communication bus 2. For example, it may be configured that data transmission is started when the state in which the signal level of the network communication bus 2 corresponds to "1" continues for a certain period of time or longer. If communication has already been started by the other slave node device 12, such a signal level state cannot be obtained.
本実施形態の構成によれば、図4に示されるように、調停負けにより送信に失敗したスレーブノード装置からのデータの再送信タイミングが早められるので、特定のスレーブノード装置から送信されるデータが調停に負け続ける事態を回避しやすくなる。具体的には、スレーブノード装置BからのデータD2の再送信タイミングが早められているので、送信タイミングが当初のままであるスレーブノード装置AからのデータD3の送信タイミングの到来時には、スレーブノード装置BからのデータD2の再送信が既に開始されている。したがって、データD3の送信は行なわれない。データD3は、さらに次の送信許可信号Pへの応答としての再送信の対象とされる。よって、特定のスレーブノード装置から送信されるデータの調停負けに伴う受信の遅延を抑制できる。
According to the configuration of the present embodiment, as shown in FIG. 4, the timing of retransmitting the data from the slave node device that failed to be transmitted due to the arbitration loss is accelerated, so that the data transmitted from the specific slave node device can be obtained. It becomes easier to avoid the situation of continuing to lose the mediation. Specifically, since the retransmission timing of the data D2 from the slave node device B has been advanced, the slave node device when the transmission timing of the data D3 from the slave node device A, which is the same as the initial transmission timing, arrives. Retransmission of data D2 from B has already started. Therefore, the data D3 is not transmitted. The data D3 is further subject to retransmission in response to the next transmission permission signal P. Therefore, it is possible to suppress the delay in reception due to the arbitration loss of the data transmitted from the specific slave node device.
各スレーブノード装置12は、再送信タイミングを早める処理を行なうに際して、データのヘッダ領域に含まれる優先度情報を変更していない。すなわち、予め定められた複数のスレーブノード装置間の優先度に係る関係は維持されている。図4に示される例の場合、スレーブノード装置Aの優先度がスレーブノード装置Bの優先度よりも高いという事実に変わりはない。しかしながら、調停負けしたデータD2に関する限りにおいて、再送信タイミングが早められることによって、スレーブノード装置Bの優先度がスレーブノード装置Aの優先度よりも暫定的に高められている。
Each slave node device 12 does not change the priority information included in the data header area when performing the process of accelerating the retransmission timing. That is, the relationship regarding the priority between the plurality of predetermined slave node devices is maintained. In the case of the example shown in FIG. 4, there is no change in the fact that the priority of the slave node device A is higher than the priority of the slave node device B. However, as far as the data D2 that has lost the arbitration is concerned, the priority of the slave node device B is tentatively higher than the priority of the slave node device A by accelerating the retransmission timing.
このような構成によれば、優先度情報を書き替える処理が不要であるので、スレーブノード装置12におけるプロセッサ122の処理負荷の増大を抑制できる。特に優先度情報がスレーブノード装置12の識別情報を兼ねるような構成においては、識別処理に与える影響を抑制できる。
According to such a configuration, since the process of rewriting the priority information is unnecessary, it is possible to suppress an increase in the processing load of the processor 122 in the slave node device 12. In particular, in a configuration in which the priority information also serves as the identification information of the slave node device 12, the influence on the identification process can be suppressed.
図4においては、二つのスレーブノード装置12から送信されるデータ同士の競合が例示されている。しかしながら、より多くのスレーブノード装置12がネットワーク通信バス2に接続される場合、データの調停負けは、複数のスレーブノード装置において発生する可能性がある。この場合、当該複数のスレーブノード装置により再送信されたデータ同士の間で再び競合が生じ、調停処理が行なわれる。例えば、再送信に供されるデータD2が、スレーブノード装置Bよりも高い優先度が付与されたスレーブノード装置C(不図示)から送信されるデータD4(不図示)によって再び調停に負ける場合がありうる。
FIG. 4 illustrates a conflict between data transmitted from the two slave node devices 12. However, when more slave node devices 12 are connected to the network communication bus 2, data arbitration loss may occur in a plurality of slave node devices. In this case, conflict occurs again between the data retransmitted by the plurality of slave node devices, and the arbitration process is performed. For example, the data D2 to be retransmitted may lose arbitration again due to the data D4 (not shown) transmitted from the slave node device C (not shown) to which the priority is given higher than that of the slave node device B. It is possible.
このような状況に対応するために、図3に破線で例示されるように、各スレーブノード装置12のプロセッサ122は、データの送信に失敗する度に、再送信タイミングをさらに早める処理を行ないうる。図4に示される例において、データD2がデータD4との調停に負けて再び送信に失敗した場合(STEP4においてYES)、プロセッサ122は、データD2が再送信されるタイミングをさらに早める処理を行なう(STEP5)。換言すると、次に送信許可信号Pが受信されてからデータの再送信が開始されるまでの時間長が、現行値であるT2からT3(不図示)へ短縮される。時間長T3は、例えば100マイクロ秒である。
In order to deal with such a situation, the processor 122 of each slave node device 12 may perform a process of further advancing the retransmission timing each time the data transmission fails, as illustrated by the broken line in FIG. .. In the example shown in FIG. 4, when the data D2 loses the arbitration with the data D4 and fails to transmit again (YES in STEP4), the processor 122 performs a process of further accelerating the timing at which the data D2 is retransmitted (YES in STEP4). STEP5). In other words, the time length from the next reception of the transmission permission signal P to the start of data retransmission is shortened from the current value T2 to T3 (not shown). The time length T3 is, for example, 100 microseconds.
これにより、次にマスタノード装置から送信される送信許可信号Pへの応答時においてデータD2が調停負けする確率をさらに低下させることができる。よって、特定のスレーブノード装置から送信されるデータの調停負けに伴う受信の遅延をさらに抑制できる。
As a result, the probability that the data D2 will lose the arbitration at the time of the next response to the transmission permission signal P transmitted from the master node device can be further reduced. Therefore, it is possible to further suppress the delay in reception due to the loss of arbitration of the data transmitted from the specific slave node device.
上記の例においては、あるデータが調停負けに伴って送信に失敗する度に、再送信タイミングを規定する時間長が300マイクロ秒から200マイクロ秒へ、200マイクロ秒から100マイクロ秒へと短縮されている。すなわち、再送信タイミングが早められる時間量は100マイクロ秒とされている。しかしながら、当該時間量は、当初の送信タイミングを規定する時間長T1、およびネットワーク通信バス2へ同時にデータを送信可能なスレーブノード装置12の数に基づいて定められうる。
In the above example, each time a piece of data fails to be transmitted due to arbitration loss, the time length that defines the retransmission timing is shortened from 300 microseconds to 200 microseconds and from 200 microseconds to 100 microseconds. ing. That is, the amount of time for which the retransmission timing is advanced is set to 100 microseconds. However, the amount of time can be determined based on the time length T1 that defines the initial transmission timing and the number of slave node devices 12 that can simultaneously transmit data to the network communication bus 2.
例えば、10個のスレーブノード装置12がネットワーク通信バス2へ同時にデータを送信可能である場合、送信許可信号Pの受信からデータの再送信開始までの時間長が当初の時間長T1から10段階で短縮されうる値として、上記の時間量が定められうる。このような構成によれば、特定のスレーブノード装置12から送信されるデータが最後まで調停に負け続けることがない。このとき、ネットワーク通信バス2へ同時にデータを送信可能なスレーブノード装置12の数と再送信開始までの時間長を短縮可能な段階の数が一致している必要はない。再送信開始までの時間長を短縮可能な段階の数を、ネットワーク通信バス2へ同時にデータを送信可能なスレーブノード装置12の数以下の範囲で多くすることにより、特定のスレーブノード装置12から送信されるデータが調停に負け続ける可能性を低減できる。
For example, when 10 slave node devices 12 can simultaneously transmit data to the network communication bus 2, the time length from the reception of the transmission permission signal P to the start of data retransmission is 10 steps from the initial time length T1. The above amount of time can be defined as a value that can be shortened. According to such a configuration, the data transmitted from the specific slave node device 12 does not continue to lose the arbitration until the end. At this time, it is not necessary that the number of slave node devices 12 capable of simultaneously transmitting data to the network communication bus 2 and the number of steps capable of shortening the time length until the start of retransmission are the same. Transmission from a specific slave node device 12 by increasing the number of steps that can shorten the time until the start of retransmission is within the range equal to or less than the number of slave node devices 12 that can simultaneously transmit data to the network communication bus 2. It is possible to reduce the possibility that the data to be generated will continue to lose the mediation.
なお、再送信タイミングが早められる時間量は、ネットワーク通信バス2において1ビットのデータ送信に要する時間よりも長くなるように定められる。上記の例の場合、1ビットのデータ送信に要する時間は、マスタノード装置11から送信されるクロック周波数に基づいて定まる。このような構成によれば、調停に負けたデータの再送信を確実に遂行できる。
The amount of time for which the retransmission timing is advanced is set to be longer than the time required for 1-bit data transmission on the network communication bus 2. In the case of the above example, the time required for 1-bit data transmission is determined based on the clock frequency transmitted from the master node device 11. With such a configuration, it is possible to reliably perform the retransmission of the data that has lost the arbitration.
上記の実施形態は、本開示の理解を容易にするための例示にすぎない。上記の実施形態に係る構成は、本開示の趣旨を逸脱しなければ、適宜に変更・改良されうる。
The above embodiment is merely an example for facilitating the understanding of the present disclosure. The configuration according to the above embodiment may be appropriately changed or improved without departing from the spirit of the present disclosure.
上記の実施形態においては、ポーリング方式のCXPI規格に基づいて通信ネットワーク3が動作しており、ネットワーク通信バス2に接続された複数のノード装置1は、マスタノード装置11とスレーブノード装置12を含んでいる。しかしながら、送信に失敗したデータの再送信タイミングを早めるという上記の処理は、複数のノード装置1についてマスタとスレーブの区別がない通信ネットワークにも適用可能である。例えば、キャリアセンス方式のCAN(Control Area Network)規格に基づいて動作する通信ネットワークが挙げられる。データ送信失敗の原因は、調停負けに限られない。他のノード装置のデータ送信によるネットワーク通信バスの占有により、規定されたタイミングでデータの送信を行なえない場合がありうる。そのような状況もまた、データ送信失敗の一例である。
In the above embodiment, the communication network 3 operates based on the polling type CXPI standard, and the plurality of node devices 1 connected to the network communication bus 2 include the master node device 11 and the slave node device 12. I'm out. However, the above-mentioned process of accelerating the re-transmission timing of the data that has failed to be transmitted can also be applied to a communication network in which there is no distinction between a master and a slave for a plurality of node devices 1. For example, a communication network that operates based on a carrier sense type CAN (Control Area Network) standard can be mentioned. The cause of data transmission failure is not limited to mediation loss. Due to the occupation of the network communication bus by data transmission of other node devices, it may not be possible to transmit data at the specified timing. Such a situation is also an example of data transmission failure.
本開示の一部を構成するものとして、2019年5月10日に提出された日本国特許出願2019-089689号の内容が援用される。
The contents of Japanese Patent Application No. 2019-089689 filed on May 10, 2019 will be incorporated as part of this disclosure.
Claims (6)
- ネットワーク通信バスに接続されるノード装置であって、
通信インターフェースと、
前記通信インターフェースに前記ネットワーク通信バスへのデータの送信を行なわせるプロセッサと、
を備えており、
前記プロセッサは、前記データの送信に失敗した場合、当該データが再送信される再送信タイミングを早めるように構成されている、
ノード装置。 A node device connected to the network communication bus
Communication interface and
A processor that causes the communication interface to transmit data to the network communication bus.
Is equipped with
The processor is configured to accelerate the retransmission timing at which the data is retransmitted if the transmission of the data fails.
Node device. - 前記データの優先度を示す優先度情報が当該データに付与されており、
前記プロセッサは、前記優先度情報を変更することなく、前記再送信タイミングを早めるように構成されている、
請求項1に記載のノード装置。 Priority information indicating the priority of the data is attached to the data.
The processor is configured to accelerate the retransmission timing without changing the priority information.
The node device according to claim 1. - 前記プロセッサは、前記データの送信に失敗する度に、前記再送信タイミングをさらに早めるように構成されている、
請求項1または2に記載のノード装置。 The processor is configured to further advance the retransmission timing each time the data transmission fails.
The node device according to claim 1 or 2. - 前記再送信タイミングが早められる時間量は、前記ネットワーク通信バスへ同時にデータを送信可能なノード装置の数に基づいて定められる、
請求項1から3のいずれか一項に記載のノード装置。 The amount of time for which the retransmission timing is advanced is determined based on the number of node devices capable of simultaneously transmitting data to the network communication bus.
The node device according to any one of claims 1 to 3. - 前記再送信タイミングが早められる時間量は、前記ネットワーク通信バスにおいて1ビットのデータ送信に要する時間よりも長くなるように定められる、
請求項1から4のいずれか一項に記載のノード装置。 The amount of time for which the retransmission timing is advanced is set to be longer than the time required for 1-bit data transmission on the network communication bus.
The node device according to any one of claims 1 to 4. - 前記再送信タイミングは、前記ネットワーク通信バスに接続された複数のノード装置に対してデータ送信を許可する信号が前記通信インターフェースに受信されてから経過した時間に基づいて決定される、
請求項1から5のいずれか一項に記載のノード装置。 The retransmission timing is determined based on the time elapsed since the signal for permitting data transmission to the plurality of node devices connected to the network communication bus is received by the communication interface.
The node device according to any one of claims 1 to 5.
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